Biden isn't the first president to pardon a relative. Here's how the power works
https://text.npr.org/nx-s1-5213251
On his last day in office in 2001, President Bill Clinton pardoned his half-brother, Roger, who had pleaded guilty and spent a year in jail on drug charges.
He got much more flack for pardoning Marc Rich, a disgraced financier who had fled to Switzerland after being indicted for evading more than $48 million in taxes, among other charges. Rich's ex-wife Denise had donated over $1 million to Democrats and Clinton's presidential library, raising questions and a Justice Department investigation into the pardon, which ultimately found no wrongdoing by Clinton.
Trump pardoned Charles Kushner, the father of his senior advisor, and son-in-law, Jared Kushner.